Referenced in this application are:
1. U.S. Pat. No. 4,373,804;
2. Copending application by the inventor entitled "Robotic Inspection Improvements", Ser. No. 657,260 filed Oct. 3, 1984;
3. Copending application entitled "Triangulation Data Integrity", Ser. No. 657,261 filed Oct. 3, 1984; and
4. Copending application Ser. No. 207,081, now U.S. Pat. No. 4,453,082.
the disclosures of which are herein incorporated by reference.
Triangulation based optical sensors described in the above references are very useful for the measurement of contoured dimensions on parts such as sheet metal, body panels and the like. Such sensors usually have an operable range, for example say 10 mm over which they can obtain accurate distance data (say to 0.01 mm) from a standoff to a surface of say 50 mm.
When used in a manually positioned mode, these sensors can however have certain disadvantages. First, many are constructed with infra-red light sources whose spots, lines or other zones projected on the part cannot be seen directly by the operator.
Second, even when visible sources are used, the range of the part to the sensor is not often indicated except by looking at a display which can be difficult for the operator to use. In addition, it is difficult for the operator to known when he is within the range of the sensor to take valid data since all such sensors have limited ranges over which they are effective, eg. 10 mm in the above example, or even up to 25 mm where lesser resolution is provided.
For this reason, the invention discloses several techniques including both visual and aural for obviating these difficulties and providing workable manual mode sensor operation. While generally of most use with optical sensors, many of the techniques disclosed herein can be used with other non-contact ranging sensors such as ultrasonic, inductive, etc. Furthermore, use is not limited to coordinate measurement machines but can be used for machines in general such as milling machines. In addition, the disclosed ideas are of use on automatically servoed measuring machines to keep the operator informed and are not limited only to manual operation.